{"id":"UBUNTU-CVE-2026-54592","details":"Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj::Doc#each_child, when invoked recursively over a deeply nested JSON document, overflows a fixed-size stack buffer and aborts the process, leading to DoS.  In a two-step chain in ext/oj/fast.c, doc_each_child increments doc-\u003ewhere past the where_path[MAX_STACK = 100] array with no bounds check and never restores it (the doc-\u003ewhere-- is missing), so calling each_child recursively from inside the yield block drives doc-\u003ewhere beyond the array. On the next entry  the function copies the path into the 800-byte stack-local buffer save_path[MAX_STACK]  using wlen = doc-\u003ewhere - doc-\u003ewhere_path, so when the previous recursive call left doc-\u003ewhere past where_path[100] the wlen exceeds MAX_STACK and  the memcpy overflows save_path on the C stack; because the Oj::Doc parser imposes no JSON nesting-depth limit (relying on a C-stack pressure check), deeply nested attacker input reaches this path. This issue has been fixed in version 3.17.3.","modified":"2026-07-01T23:35:51.505713552Z","published":"2026-07-01T00:16:00Z","upstream":["CVE-2026-54592"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-54592"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-54592"},{"type":"REPORT","url":"https://github.com/ohler55/oj/security/advisories/GHSA-3m6q-jj5j-38c9"}],"affected":[{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.10-1","2.1.4-1","2.4.0-1","2.5.3-1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.5.3-1","binary_name":"ruby-oj"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.12.10-3","2.12.10-3build1","2.12.10-4","2.12.10-4build1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.12.10-4build1","binary_name":"ruby-oj"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.17.4-1","3.4.0-1","3.4.0-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.4.0-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.8.1-1","3.9.1-1","3.9.2-1","3.10.1-1","3.10.1-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.10.1-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.11.0-1","3.13.7-1","3.13.7-1build1","3.13.9-1","3.13.9-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.13.9-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.15.0-1","3.16.1-1","3.16.3-1","3.16.3-1build1","3.16.3-1build2"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.16.3-1build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.16.3-1build3"],"ecosystem_specific":{"binaries":[{"binary_version":"3.16.3-1build3","binary_name":"ruby-oj"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.16.3-1build3","3.16.12-1","3.16.15-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.16.15-1","binary_name":"ruby-oj"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54592.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}